中文摘要：

从Landau—Devonshire唯象理论出发，通过热力学分析得到PbZr0．4Ti0.6O3薄膜的电光效应与厚度和外加电场的关系。结果表明，生长在SrTiO3衬底上的PbZr0.4Ti0.5O3薄膜，其线性电光系数和二次电光系数都随薄膜厚度的增加而增大，且在临界厚度附近趋于饱和，对50nm厚的PbZr0.4Ti0.6O3薄膜，线性电光系数和二次电光系数分别为7．2×10^-11m／V和0．31×10^-18m^2／V^2，双折射变化随外加电场改变，由线性电光效应引起的双折射变化比二次电光效应引起的双折射变化明显。

英文摘要：

The relationship between the electro-optic（EO） effect of PbZr0.4Ti0.6 O3 thin film and the film thickncss and the additional electric field has been obtained by using the thermodynamic analysis via the Landau-Devonshire＇s phenomenological theory. The results show that the linear andquadratic EO coefficients increase with the increase of film thickness and become saturated when the film thickness is close to the critical thickness of PbZr0. 4 Ti0.6 O3 thin film on SrTiO3 substrate. The linear and quadratic EO coefficients are about 7.2 × 10^-11 m/V and 0.31 × 10^-18 m^2/V^2 respectively for 50 nm PbZr0.4Ti0.6 O3 thin film. The hirefringence change depends on the electric field, and the change resulted from the linear EO effect is more prominent than that resulted from the quadratic EO effect.